This profile is part of BuzzFeed Health’s health transformation series, where we share the stories of people who have made incredible overhauls to their health, fitness, and lifestyles. Just remember, you should always check in with a doctor before starting or changing your fitness routine.

Marcinkowski has been into sports and exercise since she was in middle school, but she was always afraid of the free weight area.

She ran track and competed in the long jump in middle and high school. But when it came to lifting weights, she was inexperienced.

"Our gym teacher would bring the boys to the free weights and the girls would stay huddled in the machine area. I'd stay on the stair stepper and treadmill," she said.

Too intimidated to lift weights and also afraid she'd get bulky if she did, Marcinkowski stuck to cardio throughout high school. "For the first two years of me getting into fitness, I wouldn't step foot into the free weight section because of how intimidating everyone and everything was."

After she graduated high school, Marcinkowski started going to the gym with her brother.

"He was always telling me how great he felt after lifting weights. I said, 'Please take me with you. I want to know what it feels like,'" she says. He showed her around the free weight area and taught her a few lifts.

"I slowly started to dabble with machines and with free weights. It started to click, and it felt great compared to cardio," she says.

That's when she decided to teach herself.

Marcinkowski turned to YouTube to learn some lifting fundamentals. She watched videos by powerlifter Mark Bell as well as hours of video tutorials, like Omar Isuf's video on how to deadlift properly.

As she collected pointers from experts, she'd go to the gym and try to figure out how to mimic their form. "I would watch myself in the mirror because it was the only way I knew. There was no one to give me pointers," she says.

"I kept going till I got it right."

By January 2015 she was lifting seriously and following online programs for workouts.

She tried different programs, like Jason Blaha's Ice Cream Fitness Program for novice lifters, and hypertrophy-specific training for putting on size.

After seven months of lifting on her own, Marcinkowski wanted to train for a weightlifting meet, but she was starting to stall on her progress. So she hired a coach to write her workouts, check in on her body composition, and advise her on her diet. He's based in Kentucky so Marcinkowski keeps a detailed training log and sends it to him every week along with videos of her lifts.

In December 2015 — less than a year since she started powerlifting — Marcinkowski entered her first competition.

To understand how badass that is, at the time Marcinkowski weighed 181 pounds, which means that she was squatting almost one and a half times her bodyweight and deadlifting almost twice her bodyweight.

By the time she competed again in July 2016, she'd gotten even stronger.

And hit some major goals in the process, like breaking 300 pounds on her squat (she squatted 303 pounds in competition) and finally besting her own 128-pound bench press, where she'd been stuck for ages. NBD, but she PR'd during the competition by benching 148.5 pounds. Her deadlift had increased to 358 pounds.

She won first place in her weight class and age division.

How does a relatively new lifter dominate? Mental toughness.

Marcinkowski says that mindset — confidence and determination, mostly — are crucial in both training and competition. In fact, she's pretty sure that breaking 128 pounds in her bench press was mostly mental.

"I was afraid 135 pounds would be too heavy — 135 pounds right over you is scary! I told myself, 'Today's the day.' You have to convince yourself, 'I'm going to do what I need to do.'"

And carbs. Carbs help, too.

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To fuel her four-days-a-week training, Marcinkowski eats a diet heavy in carbs (between 200 and 300 grams of carbs on a heavy lifting day) and protein.

"My average day is about 2,600 calories... I'm convinced that that amount of food will help me train and recover for that day or for the week," she says. Steak, grilled chicken, vegetables, and protein shakes figure heavily, as do Pop-Tarts and Lenny and Larry's Complete Cookies when she needs a sugar boost before a workout.

Next up for Marcinkowski: deciding what she wants to do career-wise and getting even stronger.